2. Nature

An exploration of nature's deadly forces, from huge underwater canyons that funnel massive waves, to a bridge built from living trees, and Europe's little-known supervolcano, which could kill millions.

3. Living on the Edge

This episode examines how humans can thrive in harsh locations, from the world's highest town to a desert town in California with no rules, and an upside-down town in the Australian outback.

4. On the Road

This high-octane episode reveals the most incredible vehicles from across the globe, from a bulletproof storm-chaser to the world's biggest terrestrial vehicle, which weighs in at 14,200 tonnes.

5. In the Air

This episode checks out incredible flying. Daredevil Scotty Bob dons a wingsuit and flies inches from sheer rock. Plus: helicopter herding, solar planes, space delivery services and more.

6. In the Water

This episode showcases marvels of marine engineering, from the part-plane, part-boat Airfish to the world's largest vessel. And Australian David Warby attempts to break the world water speed record.